Stringed musical instrument



June 10, 1930. J. DOPYERA STRINGED MUSICAL INSTRUMENT 1926 2 Sheets-Sheet l Original Filed Oct. 12,

INVEN TOR.

AT oRNEY.

.lune 10, 1930. J. DOPYERA 1,762,617'

STRINGED MUS I GAL INSTRUMENT Qrginal Filed 0G13. l2 1926. 2 SheelLs-SheetI 2 Patented June l0, 1930 UNITED STATES PATENT OFFICE JOHN DOPYERA,'OF LOS ANGELES, CALIFORNIA, ASSIGNOR- T0 GEORGE D. BEAUCHAMP,

T. E. KLEINHEYER, AND PAUL BARTH,

Application Med October 12, 1926, Serial This invention relates in general to musical instruments and more particularly to stringed musical instruments, such as guitars, banjos and the like. The main object is to provide a stringed instrument in which instead of the usual membrane or skin, I have provided one or more thin sheet metal resonators, perferably of aluminum, on which the bridge supporting the strings of the instrument is mounted. Thus the vibrations set up in the strings of the instrument when the same is being played can 4be transferred to the one or more resonators and amplified substantially, for providing a louder tone and more resonant qualities than can ordinarily be provided by the emplo ment of the usual membrane or skin.

(l'ther vand minor objects of invention will appear as the description progresses.

In the accompanying drawing I have shown a preferred embodiment of my invention, subject to modification within the scope of the appended claims Without departing from the spirit thereof. In the drawing:

Fig. 1 is a plan view of the body of an instrument such as a steel uitar with the cover omitted, showing a orm of my inventionr embod ing four resonators.

Fig. 2 is a snnilar view of an instrument embodying five resonators.

Fig. 3 is a fragmentary section of one of the resonators showing a method of supporting the bridge thereon.

Fig. 4 is a top plan view of an instrument of the character shown in Fig. 1 with a cover attached thereto.

Fi. 5 is a transverse section of the assemb ed instrument on line 5-5 of Fig. 1.

Fig. G is a transverse section of the same on 6 6 of Fig. l.

It will be understood in the consideration of this invention that -while I have shown an arrangement of resonators and a structure embodying three, four and five of such resonators, that I may vary the number and change the form of the body of the instrument as the number of resonators are varied. For instance an instrument of the ukulele or banjo ukulele type may be con- OF LOS ANGELES, CALIFORNIA BTRINGED MUSICAL INSTRUMENT No. 141,115. Renewed October 22, 1929.

the instrument; also different kinds of metals may be employed in theA manufacture of the resonators; all of these points being immaterial to my invention.

Now, referring to said drawings, my instrument has the usual body B Vwith a neck N, but in lieu ot the usual membrane` or skin stretched over the body B, I provide a cover of thin sheet metal as at'C, suitably attached to the upper edge of the bodyB by means of screws as at l, 1 etc., or otherwise. The bottom of the body B is covered preferably by a wooden member Z) attached by means of screws 2, 2 etc. or otherwise, to the lower edge of the body B.

Internally of the body I provided a central partition 3 which subdivides the in terior of the body into two compartments 4 and 5 adjacent to the cover C and the bottom Z), respectively. The partition 3 is suitably secured to the body B and is mounted on the upper edge of a band as at 6, either formed internally of the member Y) or formed separate and attached thereto by suitable means.

The partition 3 has a plurality of circular openings as at O, O etc. which are concentrically arranecd around a smaller central opening 7 in said partition. Each of the openings O is covered on the upper side of the partition 3 by means of a conically formed resonator R, which is provided with an annular bead 8. Externally ot' the beads 8 the edge portions of the resonators overlie the openings O and rest upon the upper side of the }.\artition 3. Said edge portions are clamped to the partition 3 by means of annular retaining members 7' which are secured to the partition 3 by means of screws 9, 9 etc.

The bridge A which supports the strings l0, 10 etc., of the instrument is losely supported on a spider S which may be integrally formed or of composite character and provided preierably With a cent-ral annular portion l1 concentric with the opening 7 in the partition 3 and having adially Ytermed arms rz', e etc. extended outwardly trom the portieri 1l to and overlying the centers of the resonators R, R etc. as shown in Fig'. 3.

Each of the arms a of said spider S has a iat toot 12 formed thereon which is indented at 13 on the lower side with av drill or tool so as to receive the conically formed end 14 of a screw 15 Which is centrally positioned in each oit' the resonators and is extended therethrough and held thereon by means of a nut 16. rl`he bridge A is additionally supported on a single reasonator R which is mounted in the compartment 5 ot the body and on the upper side of the bottom Z). The resonator R is attached to and supported on the bottom by means of rings r as in the case oi the resonators R, and the same is connected with the bridge A by means of a metallic spring member D which is formed by bending the member a pluralty of times in reverse directions for providing resiliency. Said member terminates in portions 17 and 18 which are, respectively, held in Contact with the resonator R and the bridge A as shown in Fig. 5.

The member D extends through the central opening 7 of partition 3 and it will be observed that the bridge A which supports the strings 10 in tension, is mounted on the spider a and on the central member D, and the vibrations set up in the strings 1() of the instrument Will be communicated through t-he bridge A and the spider S and member D to the resonator R, R etc. and the resonator R.

For convenience in playing the instru ment, especially in the case of al steel Iguitar embodying my improvements, I provide an arched rest 2O formed ot metal and overlying the bridge A and strings 10, as shown in Fig. 5, said member 20 has feet 21, 21 at the ends, Which are attached by means of screws or rivets 22 to the cover C. The member 20 thus serves as a rest for the arm or hand when the instrument is being played.

An opening 23 provided in the cover C in which the bridge A is positioned and other' openings 24, 24; are provided therein as in the case of violins and other types of instruments, by means of which the tones set up by the vibrations of the resonators Within the body may be rendered more audible than Would otherwise be possible.

In certain types of instruments I may provide on the bottom b an amplifier in the form of a horn as at H in Fig. 5, suitably attached to the member 7) and beneath the resonator R', by means of which the vibrations and tones of the instrumentmay be substantially amplified When the instrument is played betere audiences in theaters or in large halls. Also by a slight rearrangement of the resonators, the resonators R, R may likewise be provided with horns or amplifier as indicated in Fig. G in broken lines. As in other types ot instruments the strings 10 are connected to a tail piece as at T, formed of metal and suitably attached to the rear end of the body B and the other ends of the strings are connected with pegs whereby the strings may be tightened for tuning.

In attaching the resonators R to the partition 3 and the resonator R to the bottom b, the same may be spaced from said members by strips of felt, rubber or other material such as cork, for insulating the same from the members on which they are supported in order that maximuni tonal qualities may be provided.

I have found that resonators made otl aluminum so thin that the metal may be readily indented by pressure of the fingers, have peculiar resonant qualities which are not possessed by other metals, or by any metal otl lilre thickness.

I have also discovered that the provision of the annular beads 8 of angular cross section near the margins of the resonators substantially amplify the vibrations set up in the resonators. This is due to the .tact that the edges of the resonators are tighly held and the beads 8 provide readily yieldable annular p' ions intermediate the margins and the cone? which permit of a maximum rcsiliency et the cones and render the resonators more delicate and sensitive to the vibrations set up therein.

Experiments have also determined that the best results can be obtained by using three of the resonators. The use of less than three resonators substantially decreases, and the use of four slightly decreases the volume. In some cases, four resonators may be used with good results, but it is preferable to use three and never less than three.

That I claim is:

1. A stringed musical instrument including a hollow body, a top having an opening therein, a plurality ot strings held in tension over said body, a` metallic ten sioning member positioned centrally Within the body, a bridge supported by said tensioning member, and positioned adjacent said opening, a plurality of metallic resonators positioned Within the body and concentric-ally arranged With respect to said tension member, and a member having arms engaging central portions of said resonators and a central portion engaging said bridge, for the purpose described.

2. A stringed musical instrument including a body having top and bottom portions spaced apart, a partition therebetween provided With a plurality of concentrically arranged openings, a centrally formed opening being provided in said top, a plurality of metallic resonators of conical cross section mounted on said partition over said concentrically arranged openings, strings held in tension over said top, a metallic spider, a bridge on said spider adjacent the opening in said top, said spider having portions contacting with central portions of each of said resonators for communicating the vibrations set up in said strings to said resonators.

3. A stringed musical instrument comprising a body, a plurality of metallic resonators of conical cross section supported therein at their edges and having annular corrugations formed near the supporting edges thereof for imparting maximum vibrational qualities thereto, strings stretched over said body, a spider, and a bridge on said spider in direct contact with said strings, said spider connecting with the apices of said resonators for communicating the vibrations set up in the strings to the resonators.

4. A stringed musical instrument comprising a hollow body having strings held in tension thereon, a plurality of metallic resonators of conical cross section and mounted Within said body, said resonators having annular flat attaching portions and annular beads of angular cross section formed near the attaching portions, and a spider common to and engaging the apices of all of the resonators, a bridge on said spider engaging said strings for communicating the vibrations from the strings to the resonators.

5. A stringed musical instrument comprising a body having spaced top and bottom portions, a partition in said body intermediate the top and bottom portions, said top and said partition having openings therein, a plurality of conical metallic resonators mounted on said partition Within said body and overlying the openings in said partition, said resonators having marginal attaching portions and annular corrugations formed near the attaching portions, a plurality of strings held in tension over the top of said body, and a spider having portions connected with the apices of said resonators and a bridge on said spider engaging said strings for the purpose described.

6. A stringed musical instrument comprising a hollow body having an opening in the top, strings held in tension over said top, a plurality of metallic resonators supported at their margin Within said body and a spider having a plurality of arms connected with the central portions of said resonators, a bridge on said spider disposed adjacent the opening in said top and engaging said strings as described.

JOHN DOPYERA. 

